| 摘要 |
The invention relates to a process for producing saccharose-based polyol polyethers for hard polyurethane foams, consisting in alkoxylating with propylenoxide and/or ethylenoxide of some saccharose/glycerine mixtures, in a ratio of 1/1...3/1 by weight, for low and medium functionalities, or saccharose/glycerine/polyether in a ratio of 5...10/1/3/...6, by weight, for high functionalities, in the presence of KOH, as a catalyst, followed by clearing the raw alkaline polyether with natural calcium bentonite, volcanic tuffs, in the presence of water, which is removed under vacuum, and the finite polyether is separated from the solid fractions by a simple filtration. By the application of the invention, there are produced polyol polyethers of high functionality, low viscosity, light colour and acidity of maximum 0.1 mg KOH/g, with a high content of cyclic carbohydrates conferring to the polyurethane foams an intrinsic structure fire-proofing and a high reticulation density.
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